It has long been recognized that babies and toddlers require some sort of controlled drinking mechanism when they start the self-feeding process and for some time thereafter. Such devices have included and ranged from the most elemental type of baby bottle nipple to more complex spring-loaded valve mechanisms. A problem common to each is that the valve mechanisms tend to be unreliable. Reliability has, on occasion, been enhanced. And it has been enhanced often, in this inventor's experience, at a significant sacrifice in simplicity, ease of construction and cleanability.